[test] Update ParseableInterface to ModuleInterface

Also remove uses of -emit-parseable-module-interface from tests

test/ModuleInterface/ModuleCache/Inputs/check-is-forwarding-module.py

@@ -0,0 +1,8 @@
+import sys
+
+for input_path in sys.argv[1:]:
+    with open(input_path, 'r') as yaml_file:
+        # Forwarding files are YAML files that start with '---'
+        if yaml_file.read(3) != '---':
+            print("swiftmodule '%s' is not a forwarding module!" % input_path)
+            sys.exit(1)